Dilated Cardiomyopathy Causes

Dilated cardiomyopathy has a number of possible causes, which can be group into two main categories, genetic and acquired.

Inherited dilated cardiomyopathy: Genetic dilated cardiomyopathy is caused by a difference in a person’s DNA that increases the risk of developing DCM. When a person has DCM without a clear cause (unexplained or “idiopathic” DCM), it is more likely that there is a genetic cause. If there are multiple people in the same family with unexplained DCM, then it is very likely that there is a genetic cause. However, genetic DCM can sometimes seem like it only affects one person in the family, as other members may have symptoms but not realize they have the condition.

The genetic causes of dilated cardiomyopathy are not as well-understood as they are for other inherited cardiomyopathies. While our researchers and others have identified many genes that cause the condition, much work remains. Even when a genetic cause seems likely, currently available testing cannot always find it. In those cases, however, we can still make recommendations for heart testing to keep your family members safe.

Acquired dilated cardiomyopathy: Many factors can lead to dilated cardiomyopathy. Even without a genetic cause, it is possible to have more than one family member with the disease because family members tend to share similar lifestyles or environments. Causes of acquired dilated cardiomyopathy include:

• Coronary artery disease or damage from a heart attack, known as ischemic dilated cardiomyopathy
• Heart valve disease
• High blood pressure (chronic hypertension) or cholesterol
• Heart muscle infection (myocarditis)
• Chemotherapy or radiation therapy side effects
• Use of recreational drugs or certain medications
• Smoking (learn more about quitting smoking)
• Diabetes